CAREER: Biogeochemical Modification of Seawater CO2 Chemistry in Near-Shore Environments: Effect of Ocean Acidification

由于众所周知的化学原理，可以非常准确地预测由于大气二氧化碳上升而导致的公海海水二氧化碳化学的变化。另一方面，在近岸环境中，这些预测要困难得多，因为二氧化碳化学在很大程度上受到以几个小时到几个月的时间尺度运行的生物地球化学过程的影响。为了预测近岸海水二氧化碳化学成分将如何变化对海洋酸化的响应，关键是要考虑净生态系统生产量(NEP)和净生态系统钙化(NEC)的相对影响，以及这些过程可能如何改变对这一重大扰动的响应。在气专委第二工作组/第一工作组最近于2011年1月举办的关于海洋酸化对海洋生物和生态系统的影响的研讨会上，以及在2012年6月在西雅图举行的国际海洋酸化网络研讨会上，确定了解未来开放式海洋协定将如何改变近岸海水的二氧化碳化学和可变性是一项重大的关键知识差距。在这一职业奖的资助下，斯克里普斯海洋研究所的一名研究人员和他的学生将研究生物地球化学过程和NEP和NEC的相对贡献如何在具有良好特征的环境和物理条件下改变受不同底栖生物群落影响的近岸环境中的海水二氧化碳化学，以及这些过程可能如何随着海洋环境变化而改变。该小组将在夏季和冬季调查亚热带(礁顶、背礁/斑礁、泻湖、海草床、藻席)和温带(海藻床、潮间带和潮下沼泽)环境中数量有限的对比栖息地，采用一种方法，使用基于总溶解无机碳(DIC)和总碱度(TA)变化的化学计量向量法评估系统的碳循环功能和性能。这些实地研究将得到在不同开放式获取情景下对比和混合底栖生物群落的对照中观实验的补充。该项目包括两个教育部分：(1)基于探究、经验和协作学习，开发一门以研究为导向的开放式学习和生物地球化学课程；(2)与海洋探索研究所(ODI)合作，通过侧重开放式学习的教育活动，吸引来自当地代表性较低的少数群体社区的个人参与科学，并为高中生和大学生提供适度数量的实习机会，以参与这一研究项目。更广泛的影响：该项目每年夏天将直接支持一名博士生、一名初级研究技术员以及两名来自未被充分代表的少数民族(URM)的高中和大学实习生。它将有助于对80名本科生和研究生进行教育，这些本科生和研究生参加了在SIO/UCSD的整个项目期间提供的四次基于研究的海洋酸化/生物地球化学课程。将通过与对外发展处的合作，编写关于开放式获取主题的教育和课程材料，包括动手实验室、课堂和实地活动，并将这些材料提供给城市高地地区的数百名城市管理学生及其教师，这是圣地亚哥地区贫困程度最高、种族多样性最高的社区。这种合作将使URM学生能够直接参与到一个快速发展的研究领域，该领域在当地和全球范围内都具有很高的相关性。为了确保这一项目和开放式获取专题的广泛传播，研究小组将与谷歌海洋团队合作，将信息和教育材料纳入谷歌海洋探索者。

Because of well-known chemical principles, changes in the CO2 chemistry of seawater in the open ocean as a result of rising atmospheric CO2 can be predicted very accurately. On the other hand, in near-shore environments, these projections are much more difficult because the CO2 chemistry is largely modified by biogeochemical processes operating on timescales of hours to months. To make predictions on how near-shore seawater CO2 chemistry will change in response to ocean acidification (OA), it is critical to consider the relative influence of net ecosystem production (NEP) and net ecosystem calcification (NEC), and how these processes might change in response to this major perturbation. Understanding how future OA will alter near-shore seawater CO2 chemistry and variability was identified as a major critical knowledge gap at the recent IPCC WG II/WG I workshop on impacts of ocean acidification on marine biology and ecosystems in January of 2011, and also at the International Ocean Acidification Network workshop in Seattle in June of 2012. With funding from this CAREER award, a researcher at the Scripps Institute of Oceanography and his students will study how biogeochemical processes and the relative contributions from NEP and NEC modify seawater CO2 chemistry in near-shore environments influenced by different benthic communities under well characterized environmental and physical conditions, and how these processes might change in response to OA. The team will investigate a limited number of contrasting habitats in subtropical (reef crest, back/patch reef, lagoon, seagrass bed, algal mat) and temperate (kelp bed, inter- and sub-tidal, marsh) environments during summer and winter, employing a method that evaluates the function and performance of the carbon cycle of a system using a stoichiometric vector approach based on changes in total dissolved inorganic carbon (DIC) and total alkalinity (TA). These field studies will be complemented by controlled mesocosm experiments with contrasting and mixed benthic communities under different OA scenarios. The project has two educational components: (1) developing a research-driven OA and biogeochemistry course based on inquiry-, experience-, and collaborative-based learning; and (2) working with the Ocean Discovery Institute (ODI) to engage individuals from a local underrepresented minority community in science through educational activities focused on OA, and also providing a moderate number of internships for high school and college students to engage in this research project. Broader Impacts: This project will directly support one PhD student, one junior research technician, and two high school and college interns from underrepresented minorities (URM) each summer of the project. It will contribute to the education of 80 undergraduate and graduate students participating in the research based ocean acidification/biogeochemistry course offered four times throughout the duration of the project at SIO/UCSD. Education and curricular material on the topics of OA, including hands-on laboratories, classroom and field-based activities will be developed through the collaboration with the ODI and brought to hundreds of URM students and their teachers in the City Heights area, a community with the highest poverty and ethnic diversity in the San Diego region. This collaboration will enable URM students to directly engage in a rapidly evolving field of research that has high relevance at both the local and global scales. To ensure broad dissemination of this project and the topic of OA, the research team will work with the Google Ocean team to incorporate information and educational material in the Google Ocean Explorer.